Transport and distribution of ballast and other materials along railways is a common task carried out by rail maintenance entities. A variety of transport and distribution systems are available in the art. These typically include a number of hopper cars loaded with ballast material that are transported along the rails to a desired dumping location for unloading. Unloading methods include physically tipping over the entire hopper car, tipping only a hopper portion of the hopper car, opening one or more gates to allow the ballast material to flow out of the hopper, and employing one or more conveyor systems, among others.
Conveyor systems may comprise one or a plurality of conveyor belts extending longitudinally along the length of the hopper car and/or between a plurality of hopper cars. The conveyors may lie beneath the hoppers, may be disposed within the hopper, or a combination thereof. In known systems the conveyors must extend or overlap between adjacent hopper cars to enable transport of the ballast materials between cars and/or along the length of the consist for distribution. In single-belt conveyance systems, e.g. one belt extending between multiple cars, the curve causes the belt to bend, flex, or turn between cars thus causing binding or flexing of the belt and prevents operation thereof.
Gate systems employed with known conveyance systems typically include clamshell or pivoting closure mechanisms in which one or a pair of doors are pivoted between open and closed positions. Other systems may employ guillotine-style gates that slide across an opening, but such guillotine-style gates are typically employed with relatively light weight materials such as grains and organic materials. A problem with known gate systems is that it may be difficult to fully close the gate while materials are moving therethrough; the materials may become pinched, jammed, or crushed between a leading edge of the door/gate and a sidewall of the chute or hopper from which the materials are exiting. Such guillotine-style gates are typically opened and closed using a screw drive system operated by a hand crank, a pneumatic drill, or the like.
Operation of the clam shell gate systems and conveyance systems of ballast hopper cars known in the art is labor intensive, i.e. a plurality of operators are required and each must oversee and operate one or more particular parts of the operation. Known systems also subject the operators to dirty and potentially hazardous conditions. Typically, one operator is positioned on a catwalk disposed along the sides of the hopper cars to open the gates and monitor the flow of material from the hoppers onto the conveyors. The gates are opened and closed using a lever. The operator manually adjusts the degree to which the gates are opened to adjust the amount of material flowing onto the conveyor to prevent the conveyor from overloading. Once a first hopper empties, the operator moves along the catwalk to a second hopper and manually opens the gate to allow material to flow from the second hopper onto the conveyor. A second operator, typically positioned in the cab of the power unit, controls the operation of the conveyor.